school makes me depressed?

I'm a freshman girl and school makes me depressed. I'm not bullied or teased by anyone, but I don't have that many friends. That's not really the main problem though.
The reasons why I hate school is because I'm always so stressed and overwhelmed because I get piles and piles of homework and it seriously makes me anxious. Thinking about school makes me cry. I'm an intelligent girl and I'm in a few honors classes but it's all so incredibly overwhelming for me and makes me want to cry. Every morning I always beg my mom to let me stay home that day. School nights I absolutely dread the next morning. I haven't always been like this. How can I be more positive and not get so depressed over a necessity??